PASSAGE 1 A complete blood count (CBC) is one of the most useful and requested types of analysis in medical practice. A CBC searches for all the cells that exist in the blood, which are divided into three basic types: white blood cells (leukocytes), platelets, and red blood cells (erythrocytes). All of these blood cells are produced in the bone marrow and correspond to a specific exam, integrated in the CBC: erythrogram, leukogram, and thrombogram. The erythrogram studies red blood cells. Among other tests, it includes a red blood cell count, a hematocrit, and hemoglobin. When these levels are low, the patient may be suffering from anemia, which can be caused by anything from heavy menstrual bleeding to Addison’s disease. A diagnosis of polycythemia may be made if the number of red blood cells is increased. The leukogram is the test that evaluates the number of white cells present in the blood, which should vary between 4,000 and 10,000 cells per cubic millimeter in most adults. High values of white blood cells are seen with infection or severe emotional/physical stress, while AIDS and chemotherapy are two causes for low values. The thrombogram is the analysis of platelets, the cells responsible for coagulation. The main function of platelets is to help stop bleeding by helping form a clot. They do this by secreting proteins from their surface that allow them to stick to vessels and each other. Low values of platelets are seen with pregnancy or an enlarged spleen, whereas high values are seen with cancers or iron deficiency. 1. According to the accompanying text, what are the names of the three basic blood cells? a) erythrograms, leukograms, and thrombograms b) red blood cells, erythrocytes, and platelets c) leukocytes, platelets, and erythrocytes d) white blood cells, leukocytes, and platelets Explanation: The three basic blood cells are white blood cells (also called leukocytes), platelets, and red blood cells (also called erythrocytes). 2. Referring to the attached passage, what is the name of the disease characterized by a high number of red blood cells? a) thrombocytopenia b) polycythemia c) This condition was not mentioned in this passage. d) anemia Explanation: The text states that a person may be diagnosed with polycythemia if his or her red blood cells counts are increased. 3. Which statement can correctly be inferred from the accompanying passage? a) A CBC should be part of every physical exam because it tells so much about the patient’s blood. b) An elevated level of platelets is a confirmation of pregnancy in the patient. c) A CBC gives a more complete evaluation of a patient’s blood than a leukogram. d) The test of red blood cells is more informative than the tests of white blood cells and platelets. Explanation: While this is not explicitly stated in the passage, two statements provide evidence of the truth of this statement: “A complete blood count (CBC) is one of the most useful and requested types of analysis in medical practice.” “…integrated in the CBC: erythrogram, leukogram, and thrombogram.” Since the leukogram is only one part of the CBC and the CBC is defined as one of most useful tests, one may infer that the CBC would provide a more complete picture than the leukogram alone. The other answer choices cannot be inferred from the passage. Pregnancy is only one possible cause of low platelets. No part of the test is referred to as being “more informative” than another; they can all detect the possibility of important medical conditions. Finally, although the CBC is deemed highly useful, there is no evidence in this passage that it would be recommended for every single patient exam. When you infer something from a passage, you have to be able to point to specific evidence that supports your inference